Britain's dependence on the US for sigint (intelligence derived from electronic
monitoring conducted at intercept stations) has been well documented. Percy
Craddock, chair of the key Whitehall committee, the Joint Intelligence Committee
(JIC) from 1985-92 has observed that even by 1953, "Britain ceased to be
the senior intelligence partner in the alliance...the advent of phot-reconnaisance
satellites emphasised this trend; the British received the product but did not
launch their own". This alliance includes US rights to operate intercept
and missile defence sites on mainland Britain such as RAF Fylingdales, RAF Menwith
Hill and Molesworth, described as the hub of American intelligence in Europe.
In fact Menwith Hill is not even accessible to British MPs.

Successive chairs of JIC have been unambigious on the implications of Britain's
dependence on the US for communications-derived intelligence. Craddock notes
that it makes "the US alliance the decisive factor in British foreign policy".
Writing recently in Prospect on the second Iraq war, another JIC chair Rodric
Braithwaite (1992-93) stated that "the US could get on perfectly well without
GCHQ's input. GCHQ on the ohter hand, is heavily reliant on US input and would
be of little value without it.

Sources:
Know Your Enemy - How the Joint Intelligence Committee saw the World
by Percy Craddock
Published by John Murray 2002

Is the special relationship over?
by Rodric Braithwaite
Prospect, May 2003

Limits of Tolerance

British intelligence has a love-hate relationship with Israeli counterparts.
On the one hand, Britain is prepared to give
credence to Israeli sources. On the other, it can also react sharply. It has been alleged that the Government closed Mossad's London base in 1987 after it was discovered that Israeli agents had withheld from British intelligence information about a plot to assassinate a Palestinian journalist. Naji Ali, a cartoonist, was shot dead in a South Kensington street.

In 1988, Prime Minister Thatcher expelled a five-man cell and two Israeli diplomats
for using their agent Ismael Sowan for planning an operation against the Palestinian
Abdul Rahim Mustafa, who was hiding in England at the time. Sowan had apparently
infiltrated a PLO cell and was convicted for storing an arms cache in a flat
in Hull on their behalf. British intelligence had not been informed of this
operation.